This application claims the benefit and priority of related German Patent Application 10059369.0 filed on Nov. 29, 2000, which is incorporated by reference herein in its entirety.
A. Field of the Invention
The invention relates to an equalizing tank, in particular, to an equalization tank for use in a cooling-medium circuit of an air-conditioning system of a motor vehicle and having pressure-equalizing means for equalizing an excessive and/or negative pressure.
B. Background of the Invention
Equalizing tanks in fluid circuits of motor vehicles, for example, in an engine cooling circuit, require a pressure relief valve and a suction relief valve in order to not lose any cooling liquid during acceleration or deceleration of the vehicle, and to equalize changes in liquid volume of the engine cooling circuit, for example, due to changes in temperature or due to loss of cooling liquid.
Valves of this type represent a cost factor and generally have to be fitted on the equalizing tank in separate installation steps during production, which is disadvantageous. Thus, a need exists for a valve-free equalization tank that does not lose cooling liquid during acceleration or deceleration, and equalizes changes in liquid volume.
The present invention is directed to overcoming or at least reducing the effects of one or more of the problems set forth above and other problems in the prior art.
According to one aspect of the invention there has been provided an equalizing tank suitable for use in an automotive air-conditioning system that includes a fluid cooling-medium circuit, comprising: a housing defining a generally closed tank for containing the cooling-medium fluid; a pressure compensation mechanism comprising a pressure dissipation orifice that opens into the housing, wherein the orifice remains open; and structure associated with the housing that prevents the cooling-medium fluid from entering the pressure dissipation orifice during changes in fluid level within the housing.
According to one aspect of the present invention, an equalizing tank is provided comprising a housing, a pressure dissipation orifice, and a return flow line configured to provide fluid communication within the housing without fluid entering the pressure dissipation orifice.
According to another aspect of the present invention, the return flow line is positioned within a receiving depression of the housing.
According to another aspect of the present invention, the housing includes a first end and a second end, wherein the return flow line provides fluid communication between the first end and the second end of the housing.
According to another aspect of the present invention, the housing comprises a plurality of wall-like depressions protruding into the interval volume of the housing, the depressions defining a first, second, and third subvolume within the housing, a first gap providing fluid communication between the first subvolume and the second subvolume, and a second gap providing fluid communication between the second subvolume and the third subvolume.
According to a preferred aspect of the present invention, the equalizing tank further comprises a collection container, wherein the return flow line discharges into the collection container.
According to another aspect of the present invention, the return flow line is an integral part of the collection tank.
According to another preferred aspect of the present invention, the pressure dissipation orifice is positioned above a point at which the return flow line discharges into the collection container.
According to another aspect of the present invention, the equalizing tank further comprises a fluid-level gage.
According to yet another aspect of the present invention, a method of manufacturing an equalizing tank is provided comprising blow-molding a housing, the housing being formed with an opening and a receiving depression; inserting a collection container into the housing opening, the collection container including a pressure dissipation orifice; and inserting a return flow line into the receiving depression, wherein the return flow line provides fluid communication with the collection container and within the housing in a manner such that fluid does not enter the pressure dissipation orifice during changes in fluid level in the housing.
According to another aspect of the present invention, the method of manufacturing an equalizing tank further comprises inserting a fluid-level gage into the housing, the fluid-level gage being positioned in fluid communication with the collection container.
According to yet another aspect of the present invention, a method of equalizing the amount of pressure in an air-conditioning circuit is provided comprising maintaining a pressure equalization tank in fluid communication with the circuit; retaining fluid heat exchange medium within the pressure equalization tank, the tank having a first end and a second end; equalizing pressure within the tank via a pressure dissipation orifice that remains open; and flowing the fluid between the first end and the second end via a return flow line without fluid entering the pressure dissipation orifice in response to changes in fluid level in the tank.
According to another aspect of the present invention, the method of equalizing the pressure of fluid further comprises restricting fluid flow within the housing through gaps in depressions protruding into the internal volume of the housing.
According to another aspect of the present invention, the method of equalizing the pressure of fluid further comprises discharging fluid from the return flow line into a collection container.
According to another aspect of the present invention, the method of equalizing the pressure of fluid further comprises measuring the fluid-level within the tank with a fluid-level gage, the fluid-level gage comprising a circular receptacle adapted to receive a sensor, and a float surrounding at least a portion of the receptacle, wherein the fluid level gage is in fluid communication with the collection container.
According to yet another aspect of the present invention, a vehicular air-conditioning system is provided comprising a primary circuit, and an air-conditioning device that includes a stationary air-conditioning function. The primary circuit comprises a compressor, a condenser, an evaporator, and a plurality of refrigerant lines providing fluid communication between the compressor, condenser and evaporator. The stationary air-conditioning device is coupled to the first circuit via the evaporator, and comprises a cold store, a heat exchanger, an equalizing tank, and a plurality of cooling medium lines providing fluid communication between the cold store, heat exchanger, and equalizing tank. The equalizing tank comprises an equalizing tank as described above.
Further objects, features and advantages of the invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the accompanying figures of drawing.